if (auth != null) {
                    repo = new RemoteRepository.Builder(repo)
                            .setAuthentication(auth)
                            .build();
                    AuthenticationContext authCtx = AuthenticationContext.forRepository(session, repo);
                    Authentication result = new Authentication(

    <!--
      | NOTE: Don't exclude the wagons or any of their dependencies (apart from the wagon API). This would otherwise
      | provoke linkage errors for wagons contributed by build extensions. We also don't need to exclude the wagons
      | from plugins. Plugins that use wagons directly and declare the corresponding dependency will simply use a
      | wagon from their plugin realm.
     -->

//go:build linux
// +build linux

// Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//

import org.apache.maven.artifact.repository.layout.ArtifactRepositoryLayout;
import org.apache.maven.repository.Proxy;

/**
 * Abstraction of an artifact repository. Artifact repositories can be remote, local, or even build reactor or
 * IDE workspace.
 */
// TODO completely separate local and remote artifact repositories
public class MavenArtifactRepository implements ArtifactRepository {

//go:build (linux && !appengine) || darwin || freebsd || netbsd || openbsd
// +build linux,!appengine darwin freebsd netbsd openbsd

// Copyright (c) 2015-2021 MinIO, Inc.
//
// This file is part of MinIO Object Storage stack
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or

            String pomXml = PomBuilder.create()
                    .groupId("test")
                    .artifactId("test")
                    .version("1.0.0")
                    .build();

            Path pomFile = projectDir.resolve("pom.xml");
            Files.writeString(pomFile, pomXml);

            UpgradeContext context = createMockContext(projectDir);

        Metadata source = new Metadata(org.apache.maven.api.metadata.Metadata.newBuilder(
                        createMetadataFromArtifact(artifact).getDelegate(), true)
                .modelEncoding("UTF-16")
                .build());
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        new MetadataStaxWriter().write(baos, source.getDelegate());
        Metadata source2 =

	tx = db.getInstance()
	tx.Statement.SQL = strings.Builder{}

	if strings.Contains(sql, "@") {
		clause.NamedExpr{SQL: sql, Vars: values}.Build(tx.Statement)
	} else {
		clause.Expr{SQL: sql, Vars: values}.Build(tx.Statement)
	}

	return tx.callbacks.Raw().Execute(tx)

                            .mojos(getMojos().stream()
                                    .map(MojoDescriptor::getMojoDescriptorV4)
                                    .collect(Collectors.toList()))
                            .build();
                }
            }
        }
        return pluginDescriptorV4;
    }

That documentation will show up in the Swagger UI at `/docs` in your API, and it will let external developers know how to build the *external API*.

This example doesn't implement the callback itself (that could be just a line of code), only the documentation part.

/// tip

The actual callback is just an HTTP request.